The present invention relates to a conveyor/elevator web, particularly, but not exclusively, for use in a vegetable, root crop or bulb harvester.
Conveyor and elevator webs are commonly used in agriculture, particularly in root crop harvesting machines. Webs are constructed by attaching a series of transverse bars to rubber traction belting to form a conveyor belt. In order to elevate the crop being harvested, various forms of spaced flight are connected to some of the web conveyors transverse bars.
The traditional method of attaching transverse bars to rubber traction belts using metal rivets is a time consuming and technically difficult operation and therefore expensive.
The elevator web bars which provide the conveyor surface between flights can be replaced by a flexible plastic sheet, in order to provide a lighter construction with less components, a less damaging surface for the crop and a surface that is self cleaning of soil.
However the flights of the above known, sheeted elevator web constitute a large proportion of the weight of construction; also they obstruct the flow of material onto the conveyor surface and therefore reduce its potential capacity.
An object of the present invention is to provide an elevator web in which the above mentioned disadvantages are at least alleviated.
The incorporation of transverse web bars in accordance with the invention into the construction of a conveyor/elevator web provides increased support for the flexible sheet and improved means of attachment of the flexible sheet and/or the rubber traction belts.
In order to construct a conveyor web of the invention the transverse bar projections need only be sufficiently long to form button shaped or flanged pegs to locate and retain the conveyor sheet and/or the rubber traction belts.
Alternatively, in order to construct an elevator web of the invention at least some of the transverse bar projections would extend above the conveyor surface to the required height of the surface of the material being elevated to form entraining fingers.
Preferably, the transverse bars consist of a resiliently deformable material, typically rubber or polyurethane, molded onto a rigid bar or tube formed of metal or plastics material.
Alternatively, the transverse bars could be formed of metal or a rigid plastics material.
Preferably, where either the transverse bar projections or the web components being attached to the transverse bar projections, i.e. rubber traction belts, are resiliently deformable the means of attachment of the assembled components would be provided by the shape of the projections.
Alternatively, an additional fastening device, i.e. clip or retaining washer, could be used in conjunction with the transverse bar projections to provide means of attachment.
Further fingers or projections may be provided towards each end of the transverse bars to form retaining sides of the conveyor/elevator web.
Additional components may be attached to the rubber traction belts between the transverse bars to form retaining sides of the conveyor/elevator web.
Preferably, the transverse bars in conjunction with the flexible conveyor sheet form pockets in the surface of the conveyor/elevator web to assist the entraining fingers.
Preferably, the flexible conveyor sheet would overlap so that both ends of a full-length sheet would be fitted to and retained by the corresponding fingers or projections of the same transverse bar.
Alternatively, the flexible sheet may be formed by a series of short sections with the trailing end of each section overlapping the leading end of the next section.